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Valsir S.p.a
Waste and water
supply systems, underfloor heating system
and flush cisterns

Tag: scarico

The air admittance valve is a useful solution to solve many problems related to waste systems ventilation. The aerator, during its functioning, balances the depressions created by the flow of fluids into the stack and the horizontal drainage branches and prevents bad smells emissions and noise formation, by taking air directly into the system in order to allow a proper waste system ventilation.

Air admittance valve: regulations in force

The international standards for waste systems inside buildings - such as UNI EN 12056 of 2001 - define the characteristics, the configurations, the design criteria and the sizing of the system. Standards are established for appropriate ventilation of waste systems and the minimum diameters to be used in relation to the units of waste. The same technical regulations involve the use of air admittance valves, provided that they are manufactured in accordance with the relevant construction standards. UNI EN 12380 of 2014, in fact, defines the classification, the requirements, the test methods and the declaration of conformity of the air valves of gravity waste systems.

Air admittance valve: applications

Proper sizing and proper air ventilation of the waste system exclude the formation of hydrostatic pressures and depressions in the pipes, thus avoiding the bothersome noise of gurgle, the emptying of sanitary traps and consequently bad smells in the bathroom. The membrane aerator is a good solution in occasions where traditional techniques cannot be used. There follows a summary of the cases solved by installing the air admittance valve.

air admittance valveArchitectural constraints or special weather conditions

The aerator can be used to ensure waste system ventilation when it is not possible to get air directly from the roof, for example, in the case of:

  • Roof terraces, rooftop pools or solariums and the presence of people;
  • Roofs covered with high layers of snow in winter.

The solution in these cases is to install the aerator with membrane in the roof space or in a grid room where air is ensured (therefore the air valve cannot be walled), in order to facilitate the collecting of air from the air valve.

air admittance valve washbasinInsufficient or absent ventilation

The air valve can be a very useful solution even in case of waste system malfunctioning caused by

  • High distance between the waste stack and the most disadvantaged sanitary equipment;
  • Insufficient diameter of horizontal pipes to ensure an adequate supply of air inside the waste system.

In order to prevent the formation of unpleasant bubbling or hissing noise in the pipes and bad smells in the bathroom, it is possible to intervene directly on single traps and on the main waste pipe, by putting one or more specific air valves (e.g. under a washbasin or a sink).

Air admittance valve: operation

The air valve is equipped with an inner membrane that opens when negative pressures (e.g. during the drainage of wastewater) are created in the waste system, allowing the air to enter the pipe in order to balance these pressures. Then the membrane closes, avoiding the emission of bad smells.

air admittance valve closedair admittance valve open

Air admittance valve: assembly

The air valve must be assembled in line with the column, so that the membrane can work in axis with the body of the valve (with a tolerance of ± 3 °); any horizontal installation is forbidden. The air admittance valve is placed inside a grid room or inside a false ceiling, where air is ensured. It is forbidden to lay the air admittance valve in rooms without air exchange (e.g. sealed in a niche).

vent valve applications

For more information, please contact Valsir by sending an email to This email address is being protected from spambots. You need JavaScript enabled to view it. . We will be happy to provide you with the right advice

To respond better and better to the different needs of plumbers and designers paying great attention to the acoustic in waste systems, and at the same time requiring flexibility and ease of installation, the Triplus waste system adds 23 new figures of different diameters to its catalogue.

New fittings for push-fit waste systems in Triplus

nuovi raccordi per lo scarico a innesto in materiale triplus

The Triplus® push-fit soundproof waste system welcomes in the range 23 new Triplus figures that will be available from July. The new range of fittings, which includes swept bends and single or double swept branches, is designed in different diameters to meet the many professional installation requirements. This means that Valsir has taken another step towards defining a range of push-fit pipes, fittings and joints for the soundproof waste systems that can clearly stand out - as well as for extremely high mechanical and acoustic performance - also in terms of range width and depth.

The Triplus waste water system list becomes even more complete mostly thanks to the addition of:

  • Long radius bend 87°30’ available in 40, 50, 75, 90 and 110 mm diameters;
  • Sweep branch 87°30’ available in 90/90, 110/75, 110/90 and 110/110 mm diameters;
  • Double swept branch 87°30’ available in 90/90/75, 90/90/90, 110/110/75, 110/110/90 and 110/110/110 mm diameters;
  • 2-way ball branch 90° available in 110/110, 125/110 and 160/110 mm diameters;
  • 2-way ball branch 180° available in 110/110, 125/110 and 160/110 mm diameters;
  • 4-way ball branch 90° available in 110/110, 125/110 and 160/110 mm diameters.

Long radius bend: improvement compared to the classic bend

The 87°30' long radius bend represents an improvement in terms of performance if compared to the classic 87°30' bend: the system's acoustic performance and the waste outflow are increased. Therefore, it can be used in floor-to-wall connections, simplifying also video inspection.

In the absence of proper spaces in the installation at the foot of a column, the 87°30' long radius bend is a good alternative to the 90° bend, as, improving the outflow, ensures optimal performance of the system.

Sweep branch: the perfect synthesis between acoustic performance and waste flow rate

The 87°30’ sweep branch, single or double, is the perfect synthesis between the 87°30’ branch acoustic performance and the 45° branch flow rate. Using the double 87°30’ sweep branch, fewer fittings are needed in compared to the 45° branch, thus making waste systems building easier.

sweep branch45 branch90 branch

Ball branch: high delivery performance and reduced installation space

ball branchThe performance of 90° and 180° ball branch, 2-way and 4-way, are half way between the ventilation branch fitting (VBF) and the 88° branch since, if compared to the classic solution, it ensures a largest mixing volume and, by limiting the size and number of fittings necessary for the system, increases the flexibility of the connection.

Triplus® represents the latest generation of waste and drainage water systems inside buildings

Triplus is the push-fit soundproof systemTriplus is the push-fit soundproof system that includes high-performance triple layer pipes, fittings and accessories that guarantees the low levels of noise emissions required by the regulations, laws and standards in force.

Triplus ensures practical and rapid installation without the use of glues, electrical appliances or special tools, thanks to the push-fit jointing system. The special geometry of the seal and the push-fit socket guarantee total water tightness and allow the normal movements of the pipeline including those caused by thermal expansion.

The introduction of new figures, within the already complete range of Triplus water drainage and waste systems, will allow an even wider choice of possible combinations for waste systems, while maintaining the excellent native acoustic characteristics and the performance you expect from a high-quality product.

For more information, please contact Valsir by sending an email to This email address is being protected from spambots. You need JavaScript enabled to view it. . We will be happy to provide you with the right advice.

The triple layer polypropylene soundproof pipes and fittings system, TRIPLUS has obtained the Certificate of Conformity AENOR UNE EN 1451-1 “Plastic pipes for waste systems at low and high temperature inside buildings”.

In surface mounting pipe supports must be used (sliding brackets or anchor brackets) to permanently fix the pipes to the building structure in order to support the weight of the pipes, the relative components connected to them and the forces generated caused by expansion and contraction. Support systems are therefore of utmost importance for the installation of a safe and high performing waste system, also in terms of acoustics.